Due to an increasing antibiotic resistance, novel classes of antibacterial compounds with a new mode of action are acutely needed for the treatment of bacterial infections. The antibacterials should possess useful levels of activity against certain human and veterinary pathogens, including gram-positive aerobic bacteria such as multiply-resistant staphylococci and streptococci, select anaerobes such as bacteroides and clostridia species, and acid-fast microorganisms such as Mycobacterium tuberculosis and Mycobacterium avium. 
It is also important that such antibacterial agents should offer sufficient safety with a minimal toxicity and adverse effects that can preclude or limit the therapy.
Among newer antibacterial agents, oxazolidinone compounds are the most recent synthetic class of antimicrobials active against a number of pathogenic microorganisms. To date, a sole antibacterial of this class linezolid (Zyvox®) has been approved for a treatment of select gram-positive infections. While oxazolidinones represented by this drug are useful for the treatment of microbial infections, their utility is limited due to serious adverse effects. Among these, monoamine oxidase inhibition and myelosuppression or bone marrow toxicity are among key factors limiting linezolid utility, as reflected in warnings in the drug's prescribing information for Zyvox® The latter type of the oxazolidinone toxicity manifested in a bone marrow suppression (also referred to as hematopoietic toxicity or myelosuppression) was reported, for example, by Monson et al. in Clinical Infectious Diseases, 2002, vol. 35, pp. e29-31. Several adverse effects for Zyvox® (including anemia, leukopenia, pancytopenia, and thrombocytopenia) have been ascribed to this phenomenon.
None of aforementioned publications specifically contemplates compounds of the present invention, their beneficial safety profiles, their combination therapies, or their novel compositions.